Clamp assembly and method of use

ABSTRACT

A clamp for clamping a body structure in a patient. The clamp includes a flexible cable housed within a sheath. The cable and sheath extend between a clamp and a handle. The cable actuator. The cable extends through a sheath which is anchored at the clamp and the actuator for actuating jaws from a proximal end of the clamp. A malleable positioner is provided for positioning the clamp about the body structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.08/791,130, filed Feb. 13, 1997 now U.S. Pat. No. 5,855,590, which is acontinuation of U.S. patent application Ser. No. 08/595,568, filed Feb.1, 1996, now issued as U.S. Pat. No. 5,626,607, which is acontinuation-in-part of Ser. No. 08/567,996, filed Dec. 4, 1995, byinventors Donlon, Stevens, Mueller, Daniel and Gifford, now issued asU.S. Pat. No. 5,618,307, which is a continuation-in-part of applicationSer. No. 08/415,273, filed Apr. 3, 1995, by inventors Philip C. Evard etal., now issued as U.S. Pat. No. 5,536,251, and is related tocommonly-assigned U.S. patent application Ser. No. 08/173,899, filedDec. 27, 1993, now issued as U.S. Pat. No. 5,425,705, the completedisclosures of which are hereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates to less-invasive surgical instruments forclamping hollow body structures. A specific application of the presentinvention is described in connection with less-invasive devices andmethods which can be used for isolating the heart and coronary bloodvessels from the remainder of the arterial system. Another specificapplication of the present invention is for clamping of the internalmammary artery for performing a coronary artery bypass procedure.

BACKGROUND OF THE INVENTION

Various cardiovascular, neurosurgical, pulmonary, and otherinterventional procedures, including coronary artery bypass grafting,heart valve repair and replacement, septal defect repair, pulmonarythrombectomy, removal of atrial myxoma, patent foramen oval closure,treatment of aneurysms, myocardial drilling, electrophysiologicalmapping and ablation, angioplasty, atherectomy, correction of congenitaldefects, and other interventional procedures may require generalanesthesia, cardiopulmonary bypass, and arrest of cardiac function. Inorder to arrest cardiac function, the heart and coronary blood vesselsmust be isolated from the remainder of the circulatory system. Thisserves several purposes. First, such isolation facilitates infusion ofcardioplegic fluid into the coronary arteries to perfuse the myocardiumand paralyze the heart without allowing the cardioplegic fluid to bedistributed elsewhere in the patient's circulatory system. Second, suchisolation facilitates use of a cardiopulmonary bypass system to maintaincirculation of oxygenated blood throughout the circulatory system whilethe heart is stopped without allowing such blood to reach the coronaryarteries and resuscitate the heart. Third, in cardiac procedures, suchisolation creates a working space into which the flow of blood and otherfluids can be controlled or prevented so as to create an optimumsurgical environment.

Circulatory isolation of the heart and coronary blood vessels is usuallyaccomplished by placing a mechanical cross-clamp externally on theascending aorta downstream of the ostia of the coronary arteries, butupstream of the brachiocephalic artery so that oxygenated blood from thecardiopulmonary bypass system reaches the arms, neck, head, andremainder of the body. Using conventional techniques, the sternum is cutlongitudinally (a median sternotomy) thereby providing access betweenopposing halves of the anterior portion of the rib cage to the heart andother thoracic vessels and organs. Alternatively, a lateral thoracotomyis formed, wherein a large incision is made between two ribs and theribs are retracted apart. A portion of one or more ribs may bepermanently removed to optimize access.

Through this large opening in the chest, a cross-clamp is placedexternally on the ascending aorta thereby isolating the heart andcoronary arteries from the remainder of the arterial system. Frequently,the aorta must be dissected away from adjacent tissue to facilitateplacement of such a cross-clamp.

To arrest cardiac function, a catheter is introduced through thesternotomy or thoracotomy and inserted through a puncture in the aorticwall into the ascending aorta between the cross-clamp and the aorticvalve. Cardioplegic fluid is infused through the catheter into theaortic root and coronary arteries to perfuse the myocardium. Anadditional catheter may be introduced into the coronary sinus forretrograde perfusion of the myocardium with cardioplegic fluid. Inaddition, the myocardium is sometimes cooled by irrigation with coldsaline solution and/or application of ice or cold packs to the outsideof the heart. Cardiac contractions will then cease.

In surgical procedures requiring a median sternotomy or other form ofgross thoracotomy, the ascending aorta is accessible for placement of anexternal cross-clamp through the large opening in the chest. However,such open-chest surgery often entails weeks of hospitalization andmonths of recuperation time as well as pain and trauma suffered by thepatient. Moreover, the average mortality rate associated with this typeof procedure is about two to fifteen per cent for first-time surgery,and mortality and morbidity are significantly increased for reoperation.

New devices and methods are therefore desired to facilitate theperformance of cardiac procedures such as heart valve repair andreplacement, coronary artery bypass grafting, and the like, usingminimally invasive techniques, eliminating the need for a grossthoracotomy. Such techniques are described in U.S. Pat. No. 5,452,733,and application Ser. No. 08/163,241 filed Dec. 6, 1993, which areassigned to the assignee of the present invention and are incorporatedherein by reference. In those applications, methods and devices aredescribed for performing coronary artery bypass grafting, heart valverepair and replacement, and other procedures through small incisions orcannulae positioned in the chest wall, obviating the need for a grossthoracotomy. One technique described for arresting the heart during suchprocedures involves the use of a catheter which is introduced into aperipheral artery such as a femoral artery and positioned in theascending aorta. An expandable member at the distal end of the catheteris expanded within the ascending aorta to block blood flow therethrough.Cardioplegic fluid is then be infused into the aortic root and into thecoronary arteries through a lumen in the catheter, and/or in aretrograde manner through a catheter positioned in the coronary sinus,paralyzing the myocardium.

While this endovascular technique for arresting the heart providessignificant advantages over conventional open-chest techniques, in somecircumstances the use of an endovascular device for aortic partitioningmay be undesirable. For example, in some cases the patient's femoralarteries and other vessels in which such a device could be introducedmay not be suitable for such introduction, due to inadequate vesseldiameter, vessel stenosis, vascular injury, or other conditions. Inaddition, where a number of endovascular cannulae are to be introducedto support cardiopulmonary bypass, retroperfusion of cardioplegic fluid,removal of blood from the heart, and other functions, a suitablearterial location for introduction of an endovascular aorticpartitioning device may not be available. Further, it may be desirableto minimize the number of arterial punctures so as to reduce the risk ofinfection and other complications stemming from such punctures.

The present invention also provides an improved method and apparatus forclamping a patient's internal mammary artery for performing a coronaryartery bypass procedure. In order to use a mammary arterial graft in acoronary artery bypass procedure, blood flow through the target mammaryartery is temporarily stopped using a removable surgical clamp. In aconventional open-chest procedure, a relatively large, easy to handleclamp is applied by hand or with a forceps directly to the mammaryartery through the large opening in the patient's chest provided by amedian sternotomy. After the mammary artery is clamped, the mammaryartery is ligated and divided at a location downstream from the clamp tocreate a free end which is connected to the coronary artery. After thegrafting is complete, the clamp is removed by the surgeon, typically byhand or with the open forceps, to permit blood to flow through themammary artery and into the coronary artery downstream of the blockage.As discussed above, gross thoracotomies used in conventional open heartsurgery are highly traumatic to the patient and, therefore, new methodsof performing surgery on the heart using minimally-invasive techniqueshave been recently developed. A further application of the presentinvention is for clamping the internal mammary artery for performing acoronary artery bypass procedure when performing minimally invasiveheart surgery.

SUMMARY OF THE INVENTION

The present invention provides less-invasive devices and methods forclamping a body structure. An application of the present invention isdescribed in connection with temporarily clamping a patient's internalmammary artery for performing a coronary artery bypass. Although thepresent invention is described in connection with clamping of theinternal mammary artery, it is understood that the methods and apparatusdescribed herein may be used to clamp any other body structure in apatient.

In a preferred embodiment of the invention, the clamp assembly includesa clamp, a handle, and a cable housed within a sheath extending betweenthe clamp and the handle. The handle includes a cable puller and a firstsheath holder. A proximal end of a cable is connected to the cablepuller and a proximal end of the sheath is held by the first sheathholder. The clamp is coupled to the distal end of the cable and sheath.The clamp includes a first jaw which is movable between an open positionand a closed position relative to a second jaw. In a preferredembodiment, the second jaw is also movable between the open and closedpositions. The first and second jaws preferably move parallel to oneanother so that shear forces are not applied to the body structurethereby minimizing trauma to the body structure. Parallel jaws alsooffer a uniform force distribution over the length of the jaws. Thefirst and second jaws may, of course, also move in any other mannerrelative to one another. The cable puller is preferably slidably mountedto the handle. The cable puller may also be coupled to the handle in anyother manner. For example, the cable puller may be rotatably coupled tothe handle.

An actuator is coupled to the cable puller for actuating the first jaw.A spring is mounted to the handle or clamp for providing a biasing forcebetween the cable and the sheath. The spring preferably has a side whichcontacts the actuator for biasing the actuator. The actuator ispreferably threadably coupled to the cable puller so that rotation ofthe actuator changes the compression of the spring thereby changing theclamping force exerted by the first and second jaws. The spring ispreferably mounted so that the cable and cable puller extend through thespring.

The clamp assembly of the present invention provides a clamp which canbe actuated from a location remote from the clamp and is thereforesuitable for minimally invasive surgical techniques such as the coronaryartery bypass procedure described above. An advantage of the clamp ofthe present invention is that the cable and sheath are flexible so thatthe clamp can be positioned in a convenient location which does nothinder access or use of other instruments. Another advantage of thepresent invention is that the flexible cable and sheath can bepositioned through an instrument delivery member, such as a trocar,cannula, or retractor, while permitting other instruments to passthrough the same instrument delivery member with minimal interference.In this manner, the number of openings in the patient is minimized.

The clamp assembly of the present invention also preferably includes anintroducer which is releasably attached to the clamp. The introducer ismore rigid than the cable and sheath so that the introducer may be usedto position the clamp around the desired body structure. The introduceris preferably releasably coupled to the handle but may also becompletely independent of the handle. The introducer is preferablymalleable so that it can be deformed into a desired shape forpositioning the clamp around other body structures in the patient if acurved path to the clamped body structure is required.

Because the patient's chest is preferably closed during the procedureexcept for one or more small percutaneous intercostal penetrations,visualization within the thoracic cavity is usually required tofacilitate accurate positioning of the clamp and/or the deliverycannula. In an exemplary embodiment, a viewing device such as anendoscope or thoracoscope is positioned in a percutaneous intercostalpenetration in the patient's chest to facilitate viewing at least aportion of the thoracic cavity. Other viewing devices may also be usedwhich use ultrasound, transesophageal echocardiography, fluoroscopy, andthe like. Although it is preferred to use an indirect visualizationdevice, a small incision may be provided between adjacent ribs fordirect visualization.

The terms “percutaneous intercostal penetration” and “intercostalpenetration” as used herein refer to a penetration, in the form or asmall cut, incision, hole, cannula, trocar sleeve, or the like throughthe chest wall between two adjacent ribs, wherein the patient's rib cageand sternum remain substantially intact, without cutting, removing, orsignificantly displacing the ribs or sternum. These terms are intendedto distinguish between a gross thoracotomy, wherein the sternum and/orone or more ribs are cut or removed from the rib cage, or one or moreribs are retracted significantly, to create a large opening into thethoracic cavity. A “percutaneous intercostal penetration” may abut oroverlap the adjacent ribs between which it is formed, but the maximumwidth of the penetration which is available for introduction ofinstruments into the thoracic cavity will be the width of theintercostal space, bounded by two adjacent ribs in their natural,substantially undeflected positions. It should be understood that one ormore ribs may be retracted or deflected a small amount and/or a smallamount of intercostal cartilage may be removed without departing fromthe scope of the invention, however, it is an objective of the inventionto avoid the pain, trauma, and complications which result from largeincisions and/or significant deflection or cutting of ribs inconventional, open-chest techniques.

A further understanding of the nature and advantages of the inventionmay be realized by reference to the remaining portions of thespecification and drawings. It should be understood that while theinvention is described in the context of thoracoscopic surgery on themammary and coronary arteries, the system and method disclosed hereinare equally useful on other types of body structures in the abdomen,pelvis, thorax and other body cavities.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of a thoracoscopicaortic clamping device.

FIG. 2A is a side cross-sectional view of the aortic clamping device ofFIG. 1.

FIG. 2B is a distal end view of the aortic clamping device of FIG. 1.

FIG. 3 is a perspective view of a second embodiment of a thoracoscopicaortic clamping device.

FIG. 4A is a side cross-sectional view of a proximal portion of theaortic clamping device of FIG. 3.

FIG. 4B is a side cross-sectional view of a distal portion of the aorticclamping device of FIG. 3.

FIG. 4C is a distal end view of the aortic clamping device of FIG. 3.

FIG. 5A is a side cross-sectional view of a further embodiment of athoracoscopic aortic clamping device showing a proximal portion thereof.

FIG. 5B is a side cross-sectional view of a distal portion of the aorticclamping device of FIG. 5A.

FIG. 5C is a distal end view of the aortic clamping device of FIG. 5A.

FIG. 5D is a front view of a staple for closing an aortic puncture inthe aortic clamping device of FIG. 5A.

FIG. 5E is a top view of the staple of FIG. 5D.

FIGS. 6A-6D are side cross-sectional views of a distal portion of theaortic clamping device of FIGS. 5A-5D showing the delivery cannulapenetrating the aortic wall and a staple closing a puncture in theaortic wall.

FIG. 7 is a side partial cross-sectional view of a further embodiment ofa thoracoscopic aortic clamping device and delivery cannula.

FIG. 8 is a side view of a distal portion of the aortic clamping deviceof FIG. 7.

FIG. 9 is a side cross-sectional view of the delivery cannula in theaortic clamping device of FIG. 7.

FIG. 10A is a side cross-sectional view of another embodiment of anaortic clamping device and delivery cannula.

FIG. 10B is a top view of a distal portion of the aortic clamping deviceof FIG. 10A in a unclamped position.

FIG. 11 is a top view of a distal portion of the aortic clamping deviceof FIG. 10A in a clamped position.

FIGS. 12A-12B are side views showing the aortic clamping device of FIG.10A positioned in the patient's ascending aorta in an open position anda clamped position, respectively.

FIGS. 13 and 14 are side views illustrating alternative embodiments ofthe aortic clamping device of FIG. 10A positioned in the patient'sascending aorta.

FIG. 15 is a front view of a patient showing the positioning of thedelivery cannula and cardiopulmonary bypass cannulae in the patient'scirculatory system to facilitate arresting cardiac function.

FIG. 16 is a front view of the interior of a patient's thoracic cavityillustrating the positioning of the aortic clamping device of FIG. 3about the patient's ascending aorta.

FIG. 17 is an external view showing a clamp assembly having a clamp anda clamp positioner.

FIG. 18 is an exploded isometric view of the clamp of FIG. 17.

FIG. 19 is an enlarged external view of the proximal end of the clamp ofFIG. 17.

FIG. 20 is an enlarged cross-sectional view of the clamp of FIG. 19 withthe jaws in a closed position.

FIG. 21 is an enlarged cross-sectional view of the clamp of FIG. 19 withthe jaws in an open position.

FIG. 22 is an enlarged view of the distal end of the clamp positioner ofFIG. 17.

FIG. 23 is a front view of the interior of a patient's thoracic cavityillustrating the use of trocar sleeves between the patient's ribs tointroduce various thoracoscopic surgical devices into the thoraciccavity and a detachable clamp clamping the ascending aorta during asurgical procedure.

FIG. 24 is an enlarged view of a portion of FIG. 23 illustrating thedistal end of an alternative clamp positioner used with the alternativeclamp of FIGS. 23 and 24.

FIG. 25 is a side view of a further clamping assembly in which the jawsare actuated with a drive rod.

FIG. 26 is an end view of the clamp of FIG. 25 taken along line 26—26.

FIGS. 27A-B are enlarged cross-sectional views of the proximal portionof the clamp of FIG. 25 in the closed and opened positions.

FIGS. 28A-C are plan, side and end views of another clamp.

FIGS. 29A-B are side views of a further clamp in closed and openedpositions.

FIG. 30A is a side view of a further clamping assembly showing the clampin a closed position and the distal end of the clamp positioner adjacentthe clamp.

FIG. 30B illustrates the clamp of FIG. 30A in an open position withportions broken away to show internal detail.

FIG. 30C is a plan view of the distal end of the clamp positioner ofFIG. 30A.

FIG. 31A is a further clamping assembly in which the clamp positionerincludes a coaxial cable to actuate the jaws of the clamp.

FIG. 31B shows an alternative embodiment of the clamp of FIG. 31A usinga torsion spring.

FIG. 31C shows a further alternative embodiment of the clamp of FIG. 31Ain which the jaws move along straight lines relative to one another anda compression spring is used to bias the jaws.

FIG. 31D illustrates an alternative embodiment of the clamp of FIG. 31Cusing a scissors mechanism to maintain the straight line movement of thejaws.

FIG. 31E illustrates another embodiment of the clamp of FIG. 31A usingjaws with concave, opposed, atraumatic surfaces and a scissors-likeopening and closing action.

FIG. 31F illustrates a portion of the clamp of FIG. 31D providing aclamping force to a hollow body structure.

FIG. 32A illustrates a further clamping assembly using hydraulicpressure to actuate the clamp through a piston and cylinder arrangement.

FIG. 32B illustrates an alternative embodiment of the clamp of FIG. 32A.

FIG. 33A shows a clamp having jaw surfaces defined by inflatableballoons.

FIG. 33B illustrates the distal ends of the jaws of FIG. 33 with theinflatable balloons inflated to close the opposed surfaces between thejaws.

FIG. 34 is a simplified view showing a side biting clamp clamping onto ablood vessel.

FIG. 35 shows a clamp assembly with the proximal end having a handle incross-section and the distal end having a clamp in partialcross-section.

FIG. 36 shows an introducer for introducing the clamp of FIG. 35 into apatient.

FIG. 37 shows the clamp assembly of FIG. 35 with the clamp having a highclamping force.

FIG. 38 shows the jaws of the clamp partially open.

FIG. 39 shows the jaws in the fully open position.

FIG. 40 is a side view of a first jaw.

FIG. 41 is a side view of a second jaw with a jaw member attached.

FIG. 42 is a plan view of the first and second jaws.

FIG. 43 is a side view of the jaw member.

FIG. 44 is an enlarged cross-section of the clamp of FIG. 39 along lineA—A of FIG. 39.

FIG. 45 is a side view of a slide.

FIG. 46 is a plan view of the slide.

FIG. 47 is a side view of an anchor.

FIG. 48 is a plan view of the anchor.

FIG. 49 shows the malleable introducer mounted to the clamp and thehandle.

FIG. 50 is a plan view of an alternative handle for the clamp assemblyof FIGS. 35-49 with a spring force indicator.

FIG. 51 is a partial cross-sectional view of the handle of FIG. 50.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first preferred embodiment of a thoracoscopic aortic clamping deviceaccording to the invention is illustrated in FIGS. 1, 2A, and 2B. Device20 includes a tubular outer shaft 22 having a proximal end 24 and adistal end 26. Outer shaft 22 preferably has a length of about 10 to 35cm so that distal end 26 may reach the ascending aorta from a lateralside or an anterior side of the chest. A drive shaft 28 extends throughouter shaft 22 and is axially rotatable therein. A fixed jaw 30 ismounted to distal end 26 of outer shaft 22. A movable jaw 32 is mountedto distal end 33 of drive shaft 28 in opposition to jaw 30 so as tofacilitate clamping the aorta therebetween. Jaws 30, 32 each have acontact surface 34 configured to engage the exterior of the aorta, whichmay include textural features to enhance grip on the aorta. Anelastomeric pad or cover (not shown) of silicone or other low durometermaterial may further be provided over contact surfaces 34 to reducetrauma on aortic tissue.

An actuator 36 is mounted at proximal end 24 of outer shaft 22. Actuator36 includes a handle 38 mounted to proximal end 24 of outer shaft 22,and a movable handle 40 mounted to drive shaft 28. By pivoting handle 40relative to handle 38, drive shaft 28 rotates within outer shaft 22,thereby opening and closing jaws 30, 32. A pair of notched extensions 42on handles 38, 40 are configured to engage one another as the handlesare closed, providing ratcheted locking of the device to maintain thejaws in a closed position.

Device 20 further includes a delivery cannula 44 for deliveringcardioplegic fluid into the aorta while jaws 30, 32 are in a closedposition on the aorta. Delivery cannula 44 has a proximal end 46 and adistal end 48 to which a needle 50 is attached. Needle 50 is dimensionedand configured to penetrate the ascending aortic wall into the aorticlumen, preferably having a length of about 1 cm to 3 cm. A deliverylumen 52 extends through cannula 44 and is in fluid communication with aport 54 near the distal end of needle 50. A luer fitting 56 is mountedto proximal end 46 of cannula 44, and is configured to engage acomplementary luer fitting 58 mounted to the proximal end of drive shaft28. Luer fitting 56 includes a barb 60 for connecting a hose (not shown)for delivering cardioplegic fluid into delivery lumen 52. Usually, thehose will be connected to a cardioplegic fluid pump designed to delivera continual or periodic flow of cardioplegic fluid into the aorta duringa procedure.

It may be seen that jaws 30, 32 are offset from the central longitudinalaxis of outer shaft 22 and drive shaft 28 so as to permit introductionof needle 50 into the aorta upstream from the point at which jaws 30, 32clamp the aorta.

Needle 50 is usually in the range of 10 gauge to 16 gauge so as tofacilitate infusion of cardioplegic fluid into the aorta at a ratesufficient to paralyze the myocardium and to maintain such paralysis.Preferably, the size of needle 50 is minimized so that the puncture madein the ascending aorta will not bleed excessively when needle 50 iswithdrawn from the aortic wall. However, in some cases, the puncturewill require closure by means of sutures, staples, or other means, asdescribed more fully below. To avoid the need for such closure, aplurality of smaller needles may be mounted to distal end 48 of deliverycannula 44 as an alternative to a single larger needle 50. The numberand size of the needles are selected to provide an adequate total flowrate of cardioplegic fluid into the aorta, yet each needle issufficiently small, e.g. less than about 0.025 in. outer diameter, sothat each puncture need not be closed after withdrawal of the needlesfrom the aortic wall due to normal blood clotting.

A second preferred embodiment of a thoracoscopic aortic clamping deviceaccording to the invention is illustrated in FIGS. 3 and 4A-4C. In thisembodiment, device 64 includes a tubular outer shaft 66 having aproximal end 68 and a distal end 70. A tubular inner shaft 72 isslidably disposed within outer shaft 66 and has a proximal end 74 and adistal end 76. A pair of jaw extensions 78, 80 are disposed within innershaft 72, each having an outwardly angled distal portion 79, 81 to whichis attached one of offset jaws 82, 84. A core tube 86 is disposedbetween jaw extensions 78, 80 within inner shaft 72, and an inner lumen88 extends through core tube 86. Delivery cannula 44 (described above)may be inserted through inner lumen 88 so that needle 50 extendsdistally from the distal end 76 of inner shaft 72. As best illustratedin FIG. 4C, jaws 82, 84 are offset from the central longitudinal axis ofouter shaft 70 and inner shaft 76 so as to permit introduction of needle50 into the aorta upstream from the point at which jaws 82, 84 clamp theaorta. Jaws 82, 84 may have a pair of elastomeric pads 83, 85 ofsilicone or other low durometer material to reduce trauma when clampedon the aorta.

A handle 90 is attached to the proximal end 68 of outer shaft 66 andincludes a housing 92 to which is coupled a lever 94. A pin 96 extendsthrough a distal end 98 of lever 94, and is slidable within a pair ofslots 100 in housing 92. A link 102 is pivotally coupled at one end tolever 94 in a middle portion thereof, and at the other end to housing 92proximal to slots 100. Inner shaft 72 is attached at its proximal end 74to distal end 98 of lever 94. In this way, pivoting lever 94 towardhousing 92 translates the lever distally within slots 100, thustranslating inner shaft 72 distally over jaw extensions 78, 80. Distalend 76 of inner shaft 72 engages angled distal portions 79, 81 of jawextensions 78, 80, thus urging jaws 82, 84 toward each other. A spring(not shown) may be mounted between housing 92 and lever 94 to bias lever94 against housing 92 to maintain jaws 82, 84 in a closed or clampedposition.

Core tube 86 is fixed to housing 92 at a proximal end 104 thereof. Aluer fitting 106 is mounted to the exterior of housing 92 and has aninterior passage in communication with inner lumen 88. When jaws 82, 84have been clamped onto the patient's aorta, delivery cannula 44 may beinserted through inner lumen 88 until needle 50 penetrates the aorticwall upstream of jaws 82, 84. Luer fitting 56 on delivery cannula 44 maybe locked onto luer fitting 106 on housing 92. A hose may be connectedto barb 60 on delivery cannula 44 to deliver cardioplegic fluid into theaorta through delivery lumen 52.

As described above, the aortic puncture created by needle 50 maysometimes require closure after withdrawal of the needle to preventexcessive bleeding when cardiac function is restored. Such closure maybe performed by means of thoracoscopic instruments, such as stapleappliers or suturing instruments. Alternatively, a means for closing theaortic puncture may be integrated into the aortic clamping device of theinvention. An example of such a device is illustrated in FIGS. 5A-5D and6A-6D. In this embodiment, clamping device 110 comprises the same jawconfiguration, handle, and jaw closure mechanism as the embodiment ofFIGS. 3 and 4A-4B. Device 110 further includes an inner sleeve 112slidably disposed within core tube 86 and having a proximal end 114, adistal end 116 and a lumen 118 therebetween. A delivery tube 120 resideswithin lumen 118 and has a fitting 122 at its distal end to which aneedle 124 is attached.

Distal end 116 of inner sleeve 112 is configured to retain a staple 126within lumen 118. Staple 126 comprises, as shown in FIGS. 5D-5E, atleast two legs 128, 130 connected by a flexible cross member 132. Legs128, 130 have distal points 134, 136 for penetrating aortic wall tissue.In an unstressed condition, legs 128, 130 are disposed at an anglebetween about 60_ and 87_ relative to cross member 132 such that points134, 136 are closer together than the remainder of legs 128, 130. Legs128, 130 may be deflected outward so as to be parallel to each other,whereby cross member 132 is deflected into a curved configuration,(shown in phantom in FIG. 5D). When legs 128, 130 are released,cross-member 132 resiliently returns to its unstressed shape, returninglegs 128, 130 to their angled disposition. In this way, staple 126 maybe applied to the aorta with legs 128, 130 parallel, and, when released,legs 128, 130 crimp the aortic tissue therebetween without requiring aseparate crimping or closure means. In alternative configurations,staple 126 may have three, four, or more legs with inwardly disposeddistal points. Shallow axial channels (not shown) may be provided onopposing sides of lumen 118 extending proximally from distal end 116 inwhich legs 128, 130 may be retained to maintain axial alignment ofstaple 126.

As shown in FIG. 5E, cross member 132 has a bore 138 in a middle portionthereof that is larger than needle 124, but smaller than fitting 122.The staple is held within lumen 118 so that needle 124 is aligned withbore 138. As shown in FIGS. 6A-6B, by distally advancing sleeve 112 anddelivery tube 120 in tandem, needle 124 penetrates the aortic wall whilestaple 126 is applied to aorta A with legs 128, 130 parallel. Sleeve 112may then be retracted proximally while delivery tube 120 remains inposition, wherein fitting 122 holds staple 126 in the aortic wall andlegs 128, 130 return to their unstressed, angled configuration (FIG.6C). When cardioplegic fluid delivery is complete, delivery tube 120 maybe retracted, removing needle 124 from aorta A and leaving staple 126 inthe aortic wall to close the puncture created by needle 124 (FIG. 6D).

The means for actuating sleeve 112 and delivery tube 120 will bedescribed with reference to FIG. 5A. An actuation button 140 is mountedat the proximal end of housing 92 and is biased in an outward positionby a spring 142. Actuation button 140 is coupled to an adaptor 144 fixedto proximal end 146 of delivery tube 120. Adaptor 144 has an innerchamber (not shown) in communication with the interior of delivery tube120. An arm 148 on adaptor 144 has an inner passage (not shown) incommunication with the inner chamber of adaptor 144 and is configuredfor connection to a flexible tube 150. Tube 150 connects to a fitting152 mounted to housing 92, which may be connected to a hose 154 from acardioplegic fluid delivery device.

A pawl 156 is pivotally mounted to adaptor 144 and is biased by a spring(not shown) to engage a set of linear teeth 158 on housing 92, thusproviding a ratcheted locking mechanism to maintain actuator button 140in a depressed position. A catch 160 is pivotally mounted to adaptor 144and is biased in a counter-clockwise direction. As actuator button 140is depressed, delivery tube 120 advances distally relative to sleeve 112until catch 160 engages proximal end 114 of sleeve 112, at which pointneedle 124 and staple 126 are in the position shown in FIG. 6A. Furtherdepression of actuator button 140 advances delivery tube 120 and sleeve112 in tandem, allowing needle 124 and staple 126 to penetrate theaortic wall, as shown in FIG. 6B. Delivery of cardioplegic fluid intoaorta A may then be initiated through hose 154, tube 150, delivery tube120, and needle 124. When the procedure is complete, cardioplegic fluiddelivery is terminated and a release button 162 is pressed, which pivotscatch 160 in a clockwise direction, allowing sleeve 112 to retractproximally under the force of a spring 164 disposed about the proximalend of sleeve 112. At this point, sleeve 112, delivery tube 120, andstaple 126 are in the positions shown in FIG. 6C. Sleeve 112 retractsrelative to delivery tube 120 until its proximal end 114 engages arelease arm 166 on pawl 156, disengaging pawl 156 from teeth 158 andallowing delivery cannula 120 and actuator button 140 to retract. Inthis way, with the press of a single release button, needle 124 isremoved from aorta A and staple 126 is applied to aortic wall to closethe puncture created by needle 124, as illustrated in FIG. 6D. Staple126 may remain in the patient's body indefinitely, may be resorbable, ormay be surgically removed using thoracoscopic instruments after clottinghas occurred or the aortic puncture has healed.

A further embodiment of an aortic clamping device according to theinvention is illustrated in FIGS. 7-9. In this embodiment, clampingdevice 170 is constructed in large part like the embodiment of FIGS. 3and 4A-4C, except that no inner lumen 88 is required for insertion of adelivery cannula 44, and that jaws 82, 84 need not be offset from thecentral axis of shafts 66, 72 to allow the delivery cannula to penetratethe aorta upstream from the point at which the aorta is clamped. In thepresent embodiment, the need to penetrate the aorta is obviated by theuse of an endovascular delivery cannula 172 positioned within the aorticlumen between jaws 82, 84. As shown in FIG. 9, delivery cannula 172comprises a flexible shaft 174 of a biocompatible polymer such aspolyurethane, polyvinyl chloride, polyether block amide, orpolyethylene, with a distal end 176, a proximal end 178, and at leastone inner lumen 180 therebetween. A port 182 is disposed at distal end176 in fluid communication with inner lumen 180, to facilitate infusionof cardioplegic fluid into the aorta. A soft tip 184 may be provided ondistal end 176 to reduce the risk of injury to vessel walls, to theaortic valve, or to other tissue. A second lumen 186 may also beprovided with a port 188 near distal end 176, to facilitate infusion oraspiration of fluids, pressure measurement, and the like. An adaptor 190is attached to proximal end 178 and has a first arm 192 with a passage193 in communication with inner lumen 180 and a second arm 194 with apassage 195 in communication with second lumen 186. First arm 192 may beconnected to a hose from a cardioplegic fluid delivery pump, whilesecond arm 194 may be connected to a pressure measurement device,aspiration device, fluid delivery device, or the like.

As illustrated in FIGS. 7-8, delivery cannula 172 is positioned in theaorta A, with distal end 176 in the ascending aorta between thebrachiocephalic artery and the coronary ostia. Shaft 174 preferably hasa length of at least about 80 cm to allow introduction into a femoralartery and transluminal positioning of distal end 176 in the ascendingaorta. First arm 192 may be connected to a cardioplegic fluid supply196, while second arm 194 may be connected to a pressure measurementdevice 198. Jaws 82, 84 of aortic clamping device 170 are positionedabout the ascending aorta A between the brachiocephalic artery and thecoronary arteries. Jaws 82, 84 are then closed on aorta A by actuatinglever 94, which extends inner shaft 66 over angled segments 79, 81. Jaws82, 84 are closed until the opposing sides of aorta A engage one anotherand seal about the exterior of delivery cannula 172, as shown in FIG. 8.Cardioplegic fluid may then be delivered through inner lumen 180, whilethe pressure within the aorta upstream of clamping device 170 may bemeasured through second lumen 186.

Referring now to FIGS. 10A-10B and 11, a further embodiment of an aorticclamping device according to the invention will be described. In thisembodiment, aortic clamping device 200 comprises a shaft 202 having adistal end 204, a proximal end 206, and first and second lumens 208, 210extending therebetween. A flexible cable or strap 212 is slidablydisposed in first lumen 208 and extends distally through an opening 214in distal end 204. An anchor 216 is attached to the distal end of cable212. A wire 218 is slidably disposed in second lumen 210 and has a loop220 extending distally from distal end 204 of shaft 202. Loop 220 has awidth which narrows in the distal direction, so that anchor 216 may bepassed through a proximal portion of loop 220, and trapped in a distalportion of loop 220.

A handle 222 is attached to proximal end 204 of shaft 202 and has a grip224 suitable for grasping with the user's hand. A lever 226 is pivotallymounted to handle 222 and has an upper end 227 to which a spring 228 isattached to bias upper end 227 in a proximal direction. Wire 218 has asecond loop 230 at its proximal end to which is attached a flexible cord232. Cord 232 extends around a pulley 234 rotatably coupled to handle222 and attaches to upper end 227 of lever 226. A gear 233 is mounted tolever 226 and is engaged by a pawl 235 pivotally mounted to handle 222.Cable 212 extends through handle 222 and exits through an opening 236,with a proximal end 238 disposed outside of handle 222. An anchor ball240 is attached to proximal end 238 and has a width larger than that ofopening 236 to prevent passage therethrough. Anchor ball 240 may beconfigured to allow adjustment of its longitudinal position on cable 212to facilitate use of device 200 on aortas of various sizes.

Usually, aortic clamping device 200 is used in conjunction with deliverycannula 172, described above in connection with FIGS. 7-9. As shown inFIGS. 12A-12B, delivery cannula 172 is first introduced into thepatient's arterial system, usually through a femoral artery, andadvanced so that distal end 176 is in the ascending aorta A betweenbrachiocephalic artery B and coronary ostia C. Aortic clamping device200 is positioned so that distal end 204 is adjacent the aorta at thepoint it is to be clamped. As shown in FIGS. 10A-10B, cable 212 iswrapped around aorta A, usually by means of conventional thoracoscopicinstruments such as forceps and/or needle drivers, and anchor 216 isinserted through loop 220. Lever 226 is then actuated, drawing anchor216 and cable 212 proximally through lumen 210 so as to tighten cable212 around aorta A until the aortic wall seals against the exterior ofdelivery cannula 172, as shown in FIGS. 11 and 12B.

In an exemplary embodiment, as shown in FIGS. 12A-12B, delivery cannula172 has a pad 242 of silicone or other low durometer polymer fixed toits exterior near distal end 176 to minimize trauma to the aortic walland to resist movement of the cannula during clamping. A stiffener coil244 embedded in shaft 174 may also be provided to maintain the patencyof lumens 180, 186 during clamping. In addition, shaft 202 may bebendable to facilitate positioning shaft 202 through an intercostalspace with distal end 204 near the ascending aorta.

To release aortic clamping device 200 from aorta A, cable 212 may besevered by inserting a scissors or knife through side port 246 in handle222, thereby releasing tension on cable 212 and allowing the device 200to be withdrawn from the thoracic cavity. Alternatively, anchor ball 240may be configured to be removable from proximal end 238 of cable 212.Or, a release cord 248 coupled to pawl 235 may be provided to facilitatedisengaging pawl 235 from gear 233, allowing lever 226 to return to itsoutward position, thereby releasing tension on cable 212. Anchor 216 maythen be removed from loop 220 using thoracoscopic instruments, allowingdevice 200 to be removed from the thoracic cavity.

FIGS. 13 and 14 illustrate two alternative constructions of deliverycannula 172 in conjunction with aortic clamping device 200. In theembodiment of FIG. 13, delivery cannula 172 includes a balloon 250attached to shaft 174 and spaced proximally from distal end 176 asufficient distance to allow aorta A to be clamped about shaft 174distal to balloon 250. The interior of balloon 250 is in communicationwith an inflation lumen (not shown) in shaft 174 for delivery of aninflation fluid into the balloon, and is configured to fully occlude theaortic lumen when inflated. A plurality of ports 252 are provided inshaft 174 distal to balloon 250 and are in communication with anaspiration lumen (not shown) within shaft 274. In this way, when cable212 is released after a procedure, any air, fluids, thrombus, and/orother emboli which might have been produced are prevented from flowingdownstream by balloon 250, and may be aspirated from the arterial systemthrough ports 252.

In the embodiment of FIG. 14, delivery cannula 172 includes an aorticocclusion means 254 at distal end 176 of shaft 174. Occlusion means 254is configured to completely occlude the aortic lumen, and may befunnel-shaped with a tapered interior passage in communication with anaspiration lumen (not shown) in shaft 174. In this way, air, fluids,thrombus, and/or other emboli which might be produced during a proceduredistal to the point of clamping are trapped in occlusion means 254 andmay be withdrawn from the arterial system through the aspiration lumenin delivery catheter 174. Occlusion means 254 is preferably a softcollapsible material to allow it to be collapsed and inserted into asheath for introduction. The sheath may be positioned in the ascendingaorta, then retracted to allow occlusion means 254 to expand and occludeaorta A. Aortic clamping device 200 may then be used to clamp aorta Aabout shaft 174.

The method of the invention will now be described with reference toFIGS. 15 and 16. The patient is first placed on cardiopulmonary bypass,using the system illustrated in FIG. 15. A venous cannula 260 ispositioned in a vein V of the patient, preferably a femoral vein in thegroin area, and advanced into the inferior vena cava IVC and/or into theinterior of heart H to withdraw deoxygenated blood therefrom. Venouscannula 260 may alternatively be introduced thoracoscopically into theinferior vena cava IVC, into the superior vena cava SVC, or into theright atrium RA. Venous cannula 260 is connected to a cardiopulmonarybypass system 262 which receives the withdrawn blood, oxygenates theblood, and returns the oxygenated blood to an arterial return cannula264 positioned in an artery AR, preferably a femoral artery. Arterialreturn cannula 264 may alternatively be introduced thoracoscopicallydirectly into an ascending or descending portion of the aorta A.

A pulmonary venting catheter 266 may also be utilized to withdraw bloodfrom the pulmonary trunk PT. Pulmonary venting catheter 266 may beintroduced from the neck through the internal jugular vein JV andsuperior vena cava SVC, or from the groin through femoral vein V andinferior vena cava IVC. Usually, a Swan-Ganz catheter (not shown) isfirst introduced and positioned in pulmonary trunk PT using well-knowntechniques, and pulmonary venting catheter 266 is then introduced overthe Swan-Ganz catheter. Blood is withdrawn from pulmonary trunk PTthrough a port at the distal end of pulmonary venting catheter 266 andan inner lumen extending through the catheter outside of the patient'sbody. Pulmonary venting catheter 266 may further have one or moreballoons 268 at its distal end proximal to the distal port for occludingpulmonary trunk PT.

An alternative method of venting blood from pulmonary trunk PT isdescribed in U.S. Pat. No. 4,889,137, which is incorporated herein byreference. In the technique described therein, a catheter is positionedfrom the internal jugular vein JV in the neck through the right atrium,right ventricle, and pulmonary valve into the pulmonary trunk PT. Thecatheter has a coil about its periphery which holds the pulmonary valveopen so as to drain blood from pulmonary trunk PT, thereby decompressingthe left side of the heart.

For purposes of arresting cardiac function, a delivery cannula 172 maybe positioned in a femoral artery AR by a percutaneous technique such asthe Seldinger technique, or through a surgical cut-down CD. Deliverycannula 172 is advanced, usually over a guidewire (not shown), until itsdistal end 176 is disposed in the ascending aorta AA between thecoronary ostia C and the brachiocephalic artery B. Blood may be ventedfrom ascending aorta AA through a port 182 at the distal end of deliverycannula 172 in communication with inner lumen 180 in delivery cannula172, through which blood may flow to proximal end 178. The blood maythen be directed to a blood filter/recovery system 270 to remove emboli,and then returned to the patient's arterial system via CPB system 262.

Ascending aorta AA may then be clamped using one of the variousembodiments of aortic clamping device described above. FIG. 16illustrates the use of aortic clamping device 110 of FIGS. 5A-5D. Shaft66 of clamping device 110 is positioned through the chest wall and intothe thoracic cavity TC through an intercostal space I between twoadjacent ribs R. Another preferred entry for the shaft 66 is through apenetration on the patient's right hand side between the first andsecond ribs. A trocar sleeve may be positioned in the chest wall withinan intercostal space to facilitate introduction of clamping device 110.An endoscope positioned in thoracic cavity TC through and intercostalspace I may be used for visualization to facilitate accurate positioningof clamping device 110. Jaws 82, 84 are positioned on opposing sides ofascending aorta AA between brachiocephalic artery B and coronary ostia C(FIG. 15). Lever 94 is then actuated to close jaws 82, 84 on ascendingaorta AA, stopping blood flow therethrough.

When it is desired to arrest cardiac function, a cardioplegic fluid suchas potassium chloride (KCl) is delivered to the myocardium in at leastone of several ways. Clamping device 110 includes an integratedcardioplegic fluid delivery cannula 120 (FIGS. 5A-5D), which may beactivated by depressing actuator button 140 on handle 90. Needle 124will penetrate the aortic wall upstream of jaws 82, 84, and cardioplegicfluid may be delivered into the ascending aorta by means of acardioplegic fluid pump 276 connected to fitting 152 in communicationwith delivery cannula 120.

As alternative or addition to delivery by means of clamping device 110,cardioplegic fluid may be delivered in an anterograde manner from acardioplegic fluid pump 196 through inner lumen 180 in delivery cannula172 into the ascending aorta upstream of the point at which the aorta isclamped. The cardioplegic fluid flows from the ascending aorta AA intothe coronary arteries and paralyzes the myocardium. It should be notedthat, when using clamping device 110 with integrated delivery cannula120, endovascular delivery cannula 172 need not be utilized. However, itmay be desirable to utilize such a cannula to facilitate pressuremeasurement, aspiration of air, fluids, thrombus, and other emboli fromthe aortic lumen, as well as supplementary delivery of cardioplegicfluid.

In addition, cardioplegic fluid may be delivered in a retrograde mannerthrough a retroperfusion catheter 272 positioned in the coronary sinusCS. Retroperfusion catheter 272 may be positioned, usually over aguidewire (not shown), from the neck through the internal jugular veinJV and superior vena cava SVC, or from the groin through a femoral veinV and the inferior vena cava IVC. Retroperfusion catheter 272 may haveone or more balloons (not shown) at its distal end to enhancepositioning and infusion of cardioplegia into the coronary sinus.Cardioplegic fluid may thus be infused through the coronary veins intothe capillary beds, paralyzing the myocardium.

Following delivery of cardioplegic fluid into the aortic lumen, cardiacfunction will quickly cease. The patient is now prepared for aninterventional procedure to be performed. A variety of thoracoscopic,endovascular, or open surgical procedures may be performed, includingcoronary artery bypass grafting, heart valve repair and replacement,septal defect repair, pulmonary thrombectomy, removal of atrial myxoma,patent foramen ovale closure, treatment of aneurysms, myocardialdrilling, electrophysiological mapping and ablation, angioplasty,atherectomy, correction of congenital defects, and other interventionalprocedures. Less-invasive techniques for performing such procedures aredescribed in commonly-assigned copending application Ser. No.08/023,778, and application Ser. No. 08/163,241, both of which areincorporated herein by reference.

When it is desired to restore cardiac function, infusion of cardioplegicfluid through thoracoscopic delivery cannula 120, endovascular deliverycannula 172 and/or retroperfusion catheter 272 is discontinued. Blood,other fluids, air, thrombus, and other emboli within the heart orcoronary arteries may then be aspirated through inner lumen 180 ofdelivery cannula 172, as well as through venous cannula 260 and/orpulmonary venting catheter 266. Release button 162 on clamping device110 may then be depressed, causing needle 124 to retract from aorta Aand leaving a staple 126 (FIGS. 6A-6D) in the aortic wall to close thepuncture created therein. If the clamping device utilized does notinclude a means for closing the aortic puncture, conventionalthoracoscopic instruments may be used to suture or staple the aorticpuncture closed, if necessary.

Lever 94 on clamping device 110 may then be released, opening jaws 82,84 to allow warm, oxygenated blood to flow into the coronary arteries toperfuse the myocardium. Cardiac contractions will usually begin soonthereafter. In some cases, electrical defibrillation may be necessary tohelp restore cardiac function. Clamping device 110 is withdrawn from thethoracic cavity. Any trocar sleeves used in the procedure are thenremoved, and thoracoscopic incisions are sutured or stapled closed.Delivery catheter 172 and retroperfusion catheter 272 may be removedfrom the patient. Cardiopulmonary bypass is then discontinued, andarterial cannula 264, venous cannula 260, and pulmonary venting catheter266 are removed from the patient. Vascular punctures are closed.

The clamps described above are suitable for clamping hollow bodystructures in a patient, and in particular the ascending aorta, whilethe proximal end of the clamp extends through a percutaneous intercostalpenetration in the patient. The following preferred embodiments describedeployable clamps which have clamp positioners which are detachable fromthe clamps. In this manner, the clamp positioner can be removed so thatincreased visual access is provided and, furthermore, a trocar used tointroduce the clamp is available for another instrument therebyadvantageously minimizing the number of penetrations in the patient.

FIGS. 17 and 18 illustrates a clamp assembly 302 having a clamp 304releasably connected to a clamp 306 positioner. The clamp 304 includesfirst and second jaws 308, 310 having opposed atraumatic jaw surfaces312, 314. The jaw surfaces 312, 314 are generally flat although any jawsurface shape may be provided. The jaws 308, 310 are generally straightbut may be provided with any other shape such as curved. Jaw 310 ispivotally mounted to jaw 308 by a pivot pin 316 which passes through abore 318 formed in a jaw extension 320 of jaw 308. Pin 316 passesthrough a bore 322 formed at the proximal end of jaw 310.

Referring to FIGS. 19-21, clamp 304 also includes an actuator housing324 slidably mounted to jaw extension 320. The slidable actuator housing324 moves the jaw 310 between open and closed positions through a pinand slot configuration, however, any other mechanical connection may beprovided. A second pin 334 is fixed within a second bore 336 formed ofthe second jaw 310 in an interference fit. The ends of pin 334 residewithin slots 330 so that movement of actuator housing 324 in thedirection of arrow 338 of FIG. 21 causes pin 334 to move upwardly withinslots 330 thereby pivoting jaw 310 upwardly from the closed position ofFIG. 20 to the open position of FIG. 21. The distal end 326 of actuatorhousing 324 circumscribes jaw extension 320 and another slot 330 formedtherein. Slot 328 passes into the open interior 332 of actuator housing324 to permit the jaw 310 to pass therethrough when in the open positionof FIG. 21.

Jaw extension 320 includes a set of ratchet teeth 340 for locking thejaws in the closed position. The ratchet teeth 340 are engaged by a pawl342 pivotally mounted within a slot 344 at a pivot 345. Pawl 342 isbiased by a spring, not shown, to pivot in a clockwise direction. Pawlis pivoted in a counterclockwise direction using the clamp positioner306 to disengage pawl 342 from ratchet teeth 340.

Referring now primarily to FIGS. 17 and 22, clamp positioner 306includes an elongate hollow body 346 sized to fit within a trocar sleeve348 (see FIG. 23) with clamp 304 mounted to the distal end of clamppositioner 306. Hollow body 346 houses a pair of longitudinally slidablemanipulator rods 350, 352 coupled to hand grips 354, 356, respectively.Manipulator rods 350, 352 each has a lug 358, 360 which engages L-shapedslots 362, 364 formed in actuator housing 324 and jaw extension 320,respectively. Lugs 358, 360 and slots 362, 364 are sized so that thedistal end 366 of hollow body 346 pivots pawl 342 in a counter-clockwisedirection when the lugs 358, 360 are positioned in the slots 362, 364.This unlocks jaw 310 and permits moving the jaws 308, 310 to the openposition of FIG. 21 with handles 354, 356. The clamp 304 is locked againby rotating and pulling clamp positioner 306 so that the lugs 358, 360disengage from slots 362, 364 thereby releasing pawl 342 and permittingpawl 342 to return to the position of FIG. 20. The clamp positioner 306is then preferably withdrawn from thoracic cavity TC through trocarsleeve 348 leaving clamp 304 in the patient

FIGS. 23 and 24 illustrate the use of a deployable clamping assembly304A to clamp the aorta AO. The embodiments discussed below withreference to FIGS. 23-33A have like parts referred to with likereference numerals. A needle 50 penetrates the aorta for deliveringcardioplegic fluid into the patient for paralyzing the myocardium.Alternatively, cardioplegic fluid may be delivered through a cannulapositioned within the aorta as shown in FIG. 8. Clamp 304A has a pair ofopposed jaws 308A, 310A pivotally mounted to one another at a pivot 367.Jaws 308A, 310A are maintained in the closed condition against theopening force of a compression spring 368 by the engagement by a pair ofratchets 370 mounted to jaw extensions 372, 374. The distal end of clamppositioner 306A has a pair of manipulator arms 350A, 352A which engageopenings 376 in jaw extensions 372, 374 to close jaws 310A, 312A ontopulmonary artery PA. A tether 373 extends between the clamp 304A and theclamp positioner 306A so that the clamp 304A can be easily located afterthe clamp positioner 306A is removed from the patient. A separate device(not shown) can be used to disengage ratchets 370 to release jaws 308A,310A so that the clamp positioner 306A can be used to remove the clamp304A.

Clamp 304A is introduced through a trocar sleeve 348 in the closedposition of FIG. 24. Clamp 304A and the portion of the clamp positioner306A passing through trocar sleeve 348 are sized to fit within thetrocar sleeve 348 which preferably has a maximum internal dimension ofabout 20 mm by 32 mm although any size may be provided. The size oftrocar sleeve 348 is determined largely by the spacing between ribs R.The above described method may, of course, be performed using any of theclamps disclosed herein.

FIG. 25 illustrates a clamping assembly 302B having a clamp positioner306B and a clamp 304B having first and second jaws 308B, 310B. The firstjaw 310B is pivotally mounted to a threaded jaw extension 320B at apivot 316B while jaw 308B is fixed. Jaws 308B, 310B are normally biasedtowards the open position of FIG. 27B by a torsion spring (not shown).

Clamp positioner 306B includes a hollow drive body 346B which houses astabilizing rod 378. The hollow drive body 346B actuates the jaws whilethe stabilizing rod 378 stabilizes the clamp assembly against thetorsional forces produced by rotational actuation of the rotatable drivebody 346B. The actuator housing 324B includes a shoulder 325 againstwhich the jaw 310B abuts due to the force of the torsion spring (notshown). Thus, slidable movement of the actuator housing 324B, andconsequently shoulder 325, moves the jaws between the open and closedpositions. The drive body 346B has a square opening 384 at the distalend which is configured to engage a square outer surface 392 of the jawextension for rotatably driving the jaw extension 320B. The squareopening 384 may have any other shape which is adapted for rotation. Thejaw extension 320B has threads which engage the hollow actuator housing324B so that rotation of the actuator housing 324B moves the actuatorhousing 324B relative to the jaws 308B, 310B. The stabilizing rod 378has a square shaft 382 (FIG. 26) at a distal end which matingly engagesa square hole 386 formed in the jaw extension 320B. The stabilizing rod378 is coupled to a handle 380 for preventing rotation of thestabilizing rod 378. Although the handles 380, 394 are shown as discs,the handles 380, 394 may also be any other conventional hand grip.

A tether 327 is preferably attached to the clamp 304B at one end andextends through the drive body 346B. The tether 327 helps the userlocate the clamp after the clamp positioner 304B is removed from thepatient. A locking tab (not shown) is preferably provided at the handle380 for locking the tether 327 to the handle 380. The tether 327 ispreferably locked to the handle 380 so that the clamp 304B and clamppositioner 306B are coupled together when removing the clamp 304B fromthe patient. The tether 327 may be provided with any of the clampsdescribed herein.

The clamp 304B is introduced into the thoracic cavity TC through atrocar sleeve 348 while in the closed position of FIG. 25. When clamp304B is properly positioned, handle 380 is held stationary while theproximal end 394 of hollow drive body 346B is rotated thereby moving theactuator housing 324B and permitting jaws 308B, 310B to open. Once theaorta is properly positioned between jaws 308B, 310B, proximal end 394of hollow drive body 346B is rotated in the opposite direction to closethe jaws 308B, 310B. Once clamped onto the hollow structure, the clamppositioner 306B is preferably removed from the patient through trocarsleeve 348. When it is desired to remove the clamp, the tether 327 isused to locate the clamp and the clamp positioner 306B is used to removethe clamp 304B.

FIGS. 28A-28C show three different views of a clamp 304C which also usesa rotatable actuating element. Clamp 304C includes first and second jaws308C, 310C having somewhat outwardly bowed jaw surfaces 312C, 314C sothat they do not touch along their entire surfaces. Jaws 308C, 310C arealso preferably curved when viewed from the side as shown in FIG. 28C

Arms 308C, 310C are pivotally mounted to opposite ends of a clamp base396. Clamp base 396 has a threaded central hole through which a threadedshaft 398 passes. The shaft 398 rotates within the threaded hole formedin base 396 so that rotation displaces the shaft axially relative to thebase. A clamp positioner similar to that shown in FIG. 25 is preferablyused to rotate a hex-head 400 while preventing base 396 from rotating. Aconnector 402 is coupled to a distal end of the shaft 398. Connector 402is coupled to first and second jaws 308C, 310C by links 404, 406 soaxial displacement of shaft 398 moves jaws 308C, 310C between the open,solid line position to the closed, dashed line position.

FIGS. 29A and 29B illustrate a clamp 304D having a pair of jaws 308D,310D and jaw extensions 372D, 374D. The jaws 308D, 310D pivot about apivot point 408 and are normally biased to the open position of FIG. 29Bwith a spring or any other conventional biasing mechanism, not shown.Clamp 304D includes a base 396D having a threaded bore through which athreaded shaft 398D passes. Threaded shaft 398D is connected to a wedge410 at its outer end. Wedge 410 is sized to engage the opposed faces412, 414 of extensions 372D, 374D for opening and closing the jaws 308D.Thus, rotating shaft 398D, while maintaining base 396D stationary, moveswedge 410 between the position of FIG. 29A, which closes jaws 308, 310,and the position of FIG. 29B, which opens jaws 308D.

FIGS. 30A-30C illustrate a clamping assembly 302E including a first jaw308E having a jaw extension 320E housing the proximal end 416 of asecond jaw 310E. Jaw 310E is pivotally mounted to jaw extension 320E ata pivot 418. A torsion spring 420 is mounted about pivot 418 whichbiases jaws 308, 310 to the open position of FIG. 30B. In the embodimentof FIGS. 30A-30C, jaw surfaces 312E, 314E are straight, atraumatic,toothed nesting surfaces commonly known as Debakey teeth. A pawl 342E ispivotally mounted to jaw 310E. Pawl 342E includes a number of teeth 340Ewhich engage a stationary tooth 422 carried by jaw extension 320. Teeth340E are biased towards tooth 422 by a torsion spring 424.

Clamp positioner 306B includes a first part 426 and a pair of secondparts 428, 429 which slide relative to first part 426 in the directionof arrow 430. Part 426 has a hook 432 at its distal end which engages aneye 434 in jaw extension 320E. With clamp positioner 306E in theorientation of FIG. 30A and the hook 432 mounted in eye 434, the secondpart 428 is configured to engage the second jaw 310E. The second part429 is moved in a distal direction to engage pawl 342E thereby pivotingpawl 342E away from tooth 422 and permitting jaw 310E to pivot to theopen position of FIG. 30B.

The above-described embodiments of clamping assembly 302-302E allprovide a clamp which is completely separable from the clamp positioner,apart from the tether, after being clamped onto a hollow body structure.Although it is preferred to provide a clamp positioner which is alsoused to retrieve the clamp after the medical procedure, it is within thescope of the present invention to provide a separate clamp remover whichis used to remove the clamp after introduction with the clamppositioner. It also may be desired to provide the tether 327 to theclamp which extends through the trocar sleeve. Tether 327 does not takeup much room and does not hinder access to the target region but aidsretrieval of the clamp by guiding the distal end of the clamp positionerto the clamp when removing the clamp from the patient.

The following embodiments disclose jaw actuating mechanisms whichinclude a cable or hydraulic actuator. An advantage of the cable andhydraulic actuators described below is that they also do not take upmuch room in the trocar sleeve and, therefore, enhance visualization andpermit introduction of other instruments into the patient through thesame trocar sleeve.

Referring to FIG. 31A, a clamping assembly 302F having a clamp 304F anda clamp positioner 306F is shown. Clamp 304F includes jaw surfaces 312F,314F which are not parallel when the jaws are in the fully closedposition of FIG. 31. The jaw surfaces 312F, 314F are covered with aresilient, ribbed material, having nesting troughs and grooves. Thisconfiguration may be useful when the hollow body structure being clampedhas relatively thick walls (see FIG. 31E) so that when the hollow bodystructure is completely collapsed, jaws 308F, 310F will be generallyparallel.

Clamp positioner 306F includes a coaxial cable 438 having an outer,hollow sheath 440 and an inner cable 442. The distal end 444 of sheath440 terminates at a recess 446 formed in jaw extension 372F. Cable 442passes through jaw extension 372F and a compression spring 368F and issecured to the jaw extension 374F at ball end 448. Clamp positioner 306Fincludes a cable puller 450 having a distal end 452 against which aproximal end 454 of sheath 440 rests. Cable 442 passes through cablepuller 450 and a second ball end 456 fits within a ball opening 458 onthe handle 460. Handle 460 is secured to the base 462 of cable puller450 at a pivot 464 and is biased to the position of FIG. 31A by thecompression spring 466.

Coaxial cable 438 is preferably sufficiently rigid to enable the user toguide clamp 304F to the target location, often without the use ofadditional guiding structure, however, a guide rod or wire may also beused as disclosed below. Once clamp 304F is adjacent to the bodystructure to be clamped, handle 460 is pressed against base 462 therebypulling cable 442 and opening the jaws 308F, 310F. The handle 460 isthen released and spring 368F closes jaws 308F around the aorta. Ballend 456 may then be disengaged from ball opening 458 and sheath 440 canbe removed from the patient through the trocar sleeve 348 while leavingcable 442 within the patient. In this manner, cable 442 serves as atether permitting easy and rapid employment of cable sheath 440 againstclamp 304F while taking up very little space within the trocar sleeveand creating minimal interference at the target region. Alternatively,the cable sheath 440 and cable 442 may remain in the patient. Asdiscussed above, the trocar sheath through which the cable passes mayinclude a passageway for holding the cable so that the cable is notinadvertently actuated by another instrument passing through the sametrocar.

Referring to FIG. 31B, a clamp 304G including jaws 308G is shown. Atorsion spring 468 biases the jaws 308G, 310G towards one another. Theclamp 304G is substantially similar to the clamp 304F, however, the jaws308G, 310G are not parallel when the jaws 308G, 310G are open.

FIG. 31C shows a clamp 304H having jaws 308H, 310H which remain parallelthroughout their movement. Jaw 308H includes a pair of slots 441 and jaw310H includes a pair of pins 443 for maintaining the parallelrelationship between jaws 308H, 310H. Clamp 304H includes a pair ofinwardly directed tips 472 at the end of each jaw 308H, 310H. Tips 472help retain the body part between the jaws 308H, 310H and also limit themaximum compression of the body part positioned therebetween.Compression spring 368H biases jaws 308H, 310H open so that pullingcable 442 closes jaws 308H, 310H. A toothed or ratcheted latch 470 locksthe jaws 308H, 310H. Latch 470 is biased towards the latched position ofFIG. 31B by a coil torsion spring, not shown. To release latch 470,sheath 440 includes an axially movable latch engagement element, notshown. Alternatively, a separate latch release mechanism may be provided

FIG. 31D shows a clamp 304I having jaws 308I, 310I which move parallelto one another as in the embodiment of FIG. 31C. A cable 442 is attachedto a central pivot 474 and a pair of links 476 so that pulling on cable442 causes pivot 474 to move proximally thereby opening jaws 308I, 310I.The jaws 308I, 310I are biased closed by springs (not shown) coupled tothe ends of links 476, 478. Clamp 304I also includes overlappingtissue-limiting tips which helps retain the body part between the jaws308I, 310I and, furthermore, limits the overall compression of the bodypart. A safety spring or other tension-sensitive element could be usedalong cable 442 to limit the force exerted by the cable 442 for any ofthe cable actuated embodiments described herein.

FIG. 31E illustrates a clamp 304J having a pair of concave jaws 308J,310J coupled to one another at a pivot 367J. The proximal ends of jawextensions 372J, 374J are connected to a pair of links 480, 482 with thelinks being coupled to one another at a common pivot 484. Cable 442 iscoupled to pivot 367J so that pulling cable 442 causes pivots 367J and484 to be drawn towards one another thereby opening jaws 308J, 310J. Atorsion spring (not shown) is positioned at pivot 367J to bias jaws308J, 310J closed. A minimum separation distance between the jaws 308J,310J is defined by a set screw (not shown) positioned in one of thethreaded openings 488. The set screw limits how far jaws 308J, 310J canbe closed and the user selects the minimum separation distance betweenthe jaws 308J by positioning the set screw in the appropriate threadedopenings 488. FIG. 31F illustrates a relatively thick-walled hollow bodystructure 490, such as an aorta, captured between jaws 308J, 310J. Ascan be seen, the distal ends of the jaws overlap one another and helpretain the hollow body structure between the jaws.

FIG. 32A illustrates a clamp 304K actuated by a clamp positioner 306Khaving a hydraulic actuator. Links 380K, 382K are pivotally coupled to acylinder 492 by pivots 494. Cylinder 492 houses a piston 493 coupled toa piston rod 496. The distal end of piston rod 496 is connected to pivot367K so that movement of the piston rod causes jaws 308K, 310K to openand close. Cylinder 492 is supplied with hydraulic fluid through ahydraulic line 498. Clamp positioner 306K includes a syringe 500 whichsupplies hydraulic fluid to hydraulic fluid line 498 throughpressure-relief shut-off valve 502. Although it is preferred to providethe syringe 500, any other hydraulic actuator may be provided. Valve 502is closed when the desired pressure is applied to the cylinder 492. Toprevent excessive force on the body part, valve 502 limits the pressureof the hydraulic fluid. If desired, the pressure relief feature of valve502 could be adjusted according to the procedure being conducted, thecondition of the patient and other pertinent information.

FIG. 32B shows a clamp 304L which is hydraulically actuated viahydraulic line 498 and hydraulic cylinder 492L. Application of hydraulicfluid through line 498 to cylinder 492L extends piston rod 496L so thata roller 504 presses against jaw extension 372L and closes jaws 308L,310L. A torsion spring (not shown) can be used at pivot 367L and biasjaws 308L, 310L open.

FIG. 33A illustrates a clamp 304M including jaws 308M, 310M having jawsurfaces 312M, 314M defined by inflatable balloons 506, 508. Theballoons 506, 508 are coupled to hydraulic lines 498, 498M for inflatingthe balloons. FIG. 33B illustrates the balloons 506, 508 in an expanded,clamped position.

FIG. 34 illustrates a side-biting clamp 304N clamping onto a bloodvessel 510 in a manner to restrict but not prevent fluid flow throughthe blood vessel as suggested by arrow 512. Although all of the previousembodiments have been described in connection with occluding the clampedbody structure, all of the clamps disclosed herein may also be used topartially occlude the body structure in a manner similar to the clamp304N of FIG. 34.

Referring to FIG. 35, a clamp assembly 600 is shown which includes aclamp 602 and a handle 604. The handle 604 and a portion of the clamp602 are shown in cross-section. A cable 606 and a sheath 608 extendbetween the clamp 602 and handle 604. The cable 606 is housed within thesheath 608 and is connected to a cable puller 610. The cable 606 is usedfor actuating the clamp 602 as described below. The sheath 608 is heldat a first sheath holder 612 at the handle 604 and at a second sheathholder 614 at an anchor 616. The cable 606 passes through the anchor 616and is coupled to a slide 618 which is slidably coupled to the anchor616. The sheath 608 and cable 606 preferably has a length from thedistal end of the handle to the proximal end of the clamp which is atleast 6 inches, and more preferably at least 10 inches, so that theclamp can reach the internal mammary artery through an percutaneousintercostal penetration while the handle remains outside the patient'schest. The slide 618 and anchor 616 will also be described in greaterdetail below. The cable 606 preferably has a 0.018 inch outer diameterand is made of stainless steel. The sheath 608 is preferably a 0.050inch outer diameter coil spring made of stainless steel. A 0.0005 shrinktube made of polyester is placed over the coil spring to preventstretching. Any other cable and sheath may be used without departingfrom the scope of the invention. The sheath 610 and cable 606advantageously permit the introduction of other instruments through thesame instrument delivery member since the sheath 610 takes up littleroom in the instrument delivery member and can be moved to a convenientlocation which does not hinder access of other instruments through thesame instrument delivery member. The sheath 610 preferably has a maximumouter diameter of less than 0.080, and more preferably equal to or lessthan 0.050.

The clamp 602 includes a first jaw 620 and a second jaw 622. The firstand second jaws 620, 622 each include a jaw member 624 having anatraumatic jaw surface 626. The jaws 620, 622 are movable between theclosed position of FIG. 35 and the open position of FIG. 39. Although itis preferred that both jaws 620, 622 be movable between the open andclosed positions, the clamp 602 may also be configured with only thefirst jaw 620 being movable. Referring to FIGS. 40 and 41, side views ofthe first and second jaws 620, 622 are shown with the second jaw 622having the jaw member 624 attached. The jaws 620, 622 includes first,second and third slots 628, 630, 632 with the second slot 630 beingoriented substantially perpendicular to the jaw surfaces 626. The secondslot 630 of the first and second jaws 620, 622 are aligned so that a pinpassing through the second slots 630 helps maintain the first and secondjaw surfaces 626 parallel to one another throughout movement between theopen and closed positions. The first and third slots 628, 632 of each ofthe jaws 620, 622 are parallel to one another and oriented 45 (degrees)relative to the jaw surface 626. Referring to FIG. 35, first, second andthird pins 629, 631, 633 pass through the first, second and third slots628, 630, 632.

Referring to the plan view of FIG. 42, the jaws 620, 622 each include aT-shaped slot 634 for attaching the jaw members 624 to the jaws 620,622. The slots 634 include a detent 636 which engages a protrusion 639(FIG. 43) in the jaw members 624 for securing the jaw member 624 to thejaws 620, 622. The jaws 620, 622 also include side surfaces 636 whichengage one another throughout movement between the open and closedpositions. Referring to FIG. 43, the jaw member 624 has a retentiontooth 638 at the distal end which extends beyond the jaw surface 626.The retention teeth 638 help retain a clamped body structure between thejaws 620, 622 even when the jaws 620, 622 are slightly open as shown inFIG. 38. The jaw member 624 also has a rounded bumper 640 at the distalend for minimizing trauma to the patient when the clamp 602 isintroduced into the body. The jaw member 624 advantageously provides theatraumatic jaw surface 626, bumper 640 and retention tooth 638 in anintegral piece which is easily attached to the first and second jaws620, 622. The jaws 620, 622 surfaces also include ribs 635 which alsohelp retain a clamped body structure between the jaws 620, 622.

Referring to FIG. 44, an enlarged cross-sectional view of the jaws 620,622 and jaw members 624 is shown. The retention teeth 638 are preferablyoffset so that the retention teeth 638 do not interfere with one anotherwhen the jaws 620, 622 are closed. The jaw members 624 are preferablyhollow to further cushion the clamped body structure. The jaw members624 are preferably made of silicone but may be formed of any othersuitable material.

Referring to FIGS. 45 and 46, side and plan views of the slide 618 areshown. The slide 618 includes a throughhole 642 for receiving the cable606. The distal end of the cable 606 preferably has an anchor (notshown) which prevents withdrawal of the cable 606 through thethroughhole 642. The slide 618 includes first and second holes 644, 646extending through first and second sides 648, 650. The first and thirdpins 629, 633 extend through the first and second holes 644, 646 and thefirst and third slots 628, 632 of the first and second jaws 620, 622 formoving the first and second jaws 620, 622 when the slide 618 is moved.The slide 618 also includes grooves 652 extending between the first andsecond holes 644, 646.

Referring to FIGS. 47 and 48, side and plan views of the anchor 616 areshown. The anchor 614 includes central guides 654 which are positionedin the grooves 652 of the slide 618. The central guides 654 and grooves652 cooperate to help maintain the linearly slidable relationshipbetween the slide 618 and anchor 614. The central guides 654 alsoinclude holes 656 therethrough for receiving the second pin 631 whichextends through the second slots 630 in the first and second jaws 620,622. The anchor 614 has a rounded proximal end 658 which facilitateswithdrawal of the clamp 602 from the patient. The proximal end 658 alsohas the second sheath holder 614 for receiving the sheath 606. Theanchor 614 also includes four arms 615, three of which are shown inFIGS. 47 and 48, which extend between the central guides 654 and theproximal end 658.

Referring again to FIG. 35, the handle 604 includes a pair of fingerengaging elements 660 positioned on opposite sides of a cavity 662. Anactuator 664 is slidably disposed within the cavity 662 for actuatingthe first and second jaws 620, 622. The actuator 664 is positionedbetween the finger engaging elements 660 for easy manipulation with thethumb or palm of the hand. Although it is preferred to provide thefinger engaging elements 660 and centrally located actuator 664, thehandle 604 may have any other configuration such as a pistol-type handlewith a trigger actuator.

A spring 668 is positioned within the cavity 662 with the cable 606extending through the spring 668. The spring 668 provides a biasingforce between the cable 606 and the handle 604 for biasing the jaws 620,622 toward the closed position. The cable puller 610 has a threadedexterior surface 670 which matingly engages a threaded interior surface672 of the actuator 664. Alternatively, the interior surface 674 of theactuator 664 may be threadably coupled to the exterior surface 676 ofthe cable puller 610. The handle 604 also includes a guide 678 whichreceives the cable puller 610. The guide 678 preferably has a squareinternal cross-sectional shape (not shown) and the cable puller 610 hasa correspondingly sized square external cross-sectional shape (notshown) so that the cable puller 610 does not rotate within the cavity662.

The spring force which biases the jaws 620, 622 toward the closedposition is varied by changing the position of the actuator 664 therebychanging the compression of the spring 668. Referring to FIGS. 35 and37, rotation of the actuator 664 moves the actuator 664 relative to thecable puller 610 and the handle 604. The clamping force of the clampassembly 600 in FIG. 35 is low since the spring 668 is relaxed while theclamping force of the clamp assembly in FIG. 37 is high since the spring668 is compressed. Although it is preferred to threadably couple thecable puller 610 and actuator 664 together, the cable puller 610 may becoupled to the actuator 664 and handle 604 in any other manner. Forexample the cable puller 610 may be rotatably coupled to the handle 604,the actuator may be linearly stable on the cable puller, and/or thespring 668 may be a torsion spring or a cantilevered lever instead of acompression spring.

Referring to FIG. 36, the clamp assembly preferably includes anintroducer 680 for facilitating introduction of the clamp 602 into thepatient. The introducer 680 has a clamp holder 682 which is releasablyfixed to the clamp 602. The introducer 680 has a pair of prongs 684which engage a pair of holes 686 in the clamp 602. The proximal end ofthe introducer 680 has a rib 688 which engages a slot 690 in the handle604. The introducer 680 also has a malleable shaft 681 which can be bentto a desired shape. Although it is preferred to releasably couple theintroducer 680 to the handle 604, the introducer 680 may be completelyindependent of the handle 604. Referring to FIG. 49, the introducer 680has a length similar to the length of the clamp assembly 600 so that thesheath 610 is pulled taught when the introducer 680 is coupled to theclamp 602 and handle 604. In this manner, the introducer 680 retains theclamp 602 with the prongs 684. To release the clamp 602, the rib 688 isdisengaged from the slot 690 and the introducer 680 is simply pulledfrom the clamp 602 with the prongs 684 sliding out of the holes 686. Theintroducer 680 may also include an actuator for positively attaching andreleasing the clamp 602 to and from the clamp holder 682. Although it ispreferred to provide the introducer 680, the clamp 602 may also bepositioned with a conventional medical instrument such as forceps or thelike.

Referring to FIG. 50, the clamp assembly 600 also preferably includes anindicator 692 which provides a relative indication of the spring 668compression. The indicator 692 extend through a slot 694 in the handle604 and a numerical scale indicates the relative clamping force.Referring to FIG. 51, the indicator 692 is received in a circumferentialslot 696 in the distal end of the actuator 664. When the actuator 664 isrotated, the indicator 692 translates in the slot 696. The clampassembly 600 also preferably includes a clip 698 for securing the handle604 to a drape or curtain which covers the patient.

Referring to FIGS. 35, 37, 39 and 49, operation of the clamp 602 is nowdescribed in connection with clamping an internal mammary artery.Although clamping of the internal mammary artery is described as apreferred use of the clamping assembly, the clamp assembly may, ofcourse, be used for clamping any other body structure. When the jaws620, 622 are in the closed position of FIG. 35, the slide 618 is biasedtoward the proximal end by the spring 668 and is positioned near theproximal end of the anchor 614. If a high clamping force is desired, theactuator 664 is rotated to the position of FIG. 37. If a low clampingforce is desired, the actuator 664 is moved to the position of FIG. 35.The clamp 602 is then mounted to the introducer 680 as shown in FIG. 49and the clamp 602 is introduced into the patient. When the clamp 602 ispositioned near the internal mammary artery, the actuator 664 isdepressed so that the cable 606 and slide 618 move distally relative tothe sheath 610. The pin and slot configuration of the jaws 620, 622,slide 618 and anchor 614 cause the jaws 620, 622 to move to the openposition while moving parallel to one another as shown in FIG. 39. Theclamp 602 is then moved so that the internal mammary artery ispositioned between the jaws 620, 622. The actuator 664 is then releasedso that the jaws 620, 622 close around the internal mammary artery. Therib 688 of the introducer 680 is released from the handle 604 and theintroducer 680 is pulled from the clamp 602 and removed from thepatient. The handle 604 is then moved to a convenient location where itwill not interfere with the medical procedure such as grafting of theinternal mammary artery to a blocked coronary artery. After theprocedure is completed, the actuator 664 is depressed to open the jaws620, 622 and the clamp 602 is then simply pulled from the patient. Anadvantage of the clamp assembly 600 is that the clamping force may beadjusted during the procedure without requiring re-application of theclamp 602. If, for example, the clamped body structure is a blood vesselwhich is not fully occluded, the clamping force may be increased withoutreleasing the clamp 602. Referring to FIG. 38, another advantage of theclamp assembly is that the retention teeth 638 can be used to retain thebody structure even when the jaws 620, 622 are separated. After theinternal mammary artery is grafted to a downstream portion of anoccluded coronary artery, the actuator 664 is depressed to release theclamp 602 and permit blood flow through the internal mammary artery.

The clamp assembly 600 advantageously provides a clamp 602 which may beactuated at a location remote from the clamp 602 and is particularlyuseful for temporarily clamping a body structure such as an internalmammary artery. The clamp 602 may be positioned around the internalmammary artery with the cable 606 and sheath 610 extending through aninstrument delivery member such as a trocar, cannula, retractor, or thelike. Although it is preferred to provide the pin and slot configurationof the FIG. 35, it is also within the scope of the present invention touse any of the other cable actuated clamps described above with theactuator 664. Conversely, any of the actuators described above may beused with the clamp 602 of FIG. 35.

While the clamps described have been described specifically withreference to aortic clamping and clamping of the internal mammaryartery, it will be understood to those of ordinary skill in the art thatthe invention is useful in a variety of other interventional proceduresas well. For example, the clamping device of the invention may be usedfor clamping, cannulation of, and infusing fluid into blood vesselsother than the aorta, as well as hollow body structures such as thebowel, bile duct, colon, and various other tubular ducts and organs.Furthermore, all of the clamps are suited for the procedures describedherein including use of the intraluminally positionable delivery cannula172 shown in FIGS. 7, 8, and 10-14 and the tether of FIGS. 23-25. Inaddition, although each of the preferred jaw shapes may be describedwith a particular actuating mechanism, any jaw shape may be used withthe clamps and actuating mechanisms described herein and, in particular,curved and flattened tips will aid in blunt dissection. While the aboveis a complete description of the preferred embodiments of the invention,various alternatives, modifications and equivalents may be used.Therefore, the above description should not be taken as limiting thescope of the invention, which is defined by the claims.

What is claimed is:
 1. A method of clamping a structure in a patient,comprising the steps of: providing a clamp, an introducer releasablycoupled to the clamp, a cable puller, a flexible sheath, and a flexiblecable, the handle having a first sheath holder and the clamp having asecond sheath holder, the sheath extending between the first and secondsheath holders, the cable being at least partially housed within thesheath and being coupled to the cable puller, the cable puller beingadapted to displace the cable relative to the sheath, the clamp having afirst jaw and a second jaw, the first and second jaws being movablebetween an open position and a closed position, the first jaw beingcoupled to the cable so that the first jaw moves between the open andclosed positions when the cable is moved by the cable puller;introducing the clamp into a patient; moving the cable puller therebydisplacing the cable relative to the sheath and moving the first jaw tothe open position, the first and second jaws having jaw surfacesremaining substantially parallel to one another when moving between theopen and closed positions; positioning a body structure of a patientbetween the first and second jaws after the moving step, the positioningstep being carried out by manipulating the introducer so that the firstand second jaws are positioned around the body structure; and closingthe jaws around the body structure by moving the cable puller.
 2. Themethod of claim 1, further comprising the step of: disengaging theintroducer from the clamp after the positioning step.
 3. A method ofclamping a structure in a patient, comprising the steps of: providing aclamp, a cable puller, a flexible sheath, and a flexible cable, thehandle having a first sheath holder and the clamp having a second sheathholder, the sheath extending between the first and second sheathholders, the cable being at least partially housed within the sheath andbeing coupled to the cable puller, the cable puller being adapted todisplace the cable relative to the sheath, the clamp having a first jawand a second jaw, the first and second jaws being movable between anopen position and a closed position, the first jaw being coupled to thecable so that the first jaw moves between the open and closed positionswhen the cable is moved by the cable puller; introducing the clamp intoa patient; moving the cable puller thereby displacing the cable relativeto the sheath and moving the first jaw to the open position, the firstand second jaws having jaw surfaces remaining substantially parallel toone another when moving between the open and closed positions;positioning a body structure of a patient between the first and secondjaws after the moving step; closing the jaws around the body structureby moving the cable puller; and adjusting a force biasing the first andsecond jaws toward the closed position.